The overall goal of project III is to evaluate the use of I-131- labeled anti-myeloid antibodies and autologous marrow transplantation as treatment for acute nonlymphocytic leukemia. This approach is based on the ability of labeled antibody to localize to the marrow space and the utility of external beam total body irradiation (TBI) with autologous marrow transplantation in treating ANL. We will initially measure the pharmacokinetics, biodistribution and associated radiation dosimetry of varying doses of I-131-labeled anti-myeloid antibodies in patients with ANL in second (or subsequent) remission. In patients in whom we achieve favorable dosimetry, we will evaluate the effects of increasing therapeutic doses of I- 131-labeled antibody with particular attention to the ability of the antibody-conjugate to ablate marrow, recovery of hematopoiesis following autologous transplantation, and the nature and extent of extramedullary toxicities. If favorable dosimetry is not achieved we will evaluate alternatives antibodies, forms of antibody (F(ab) or F(ab')2), or antibody infusion schedules.